That gave the Mobile, Ala., couple a bigger adrenaline rush than many Whistler skiers ever get, thanks to Ziptrek Ecotours, which takes visitors on the aerial adventure.

The company's four zip lines — the 1,100-footer and three shorter ones — criss-cross a steep-walled, narrow valley between Whistler and Blackcomb mountains that's edged with centuries-old trees to which the cables are anchored. Visitors get heart-pounding rides — surging through the air at speeds up to 50 mph above the tumbling Fitzsimmons Creek — and learn a bit about old-growth forests from ecologically-minded young guides.

Zip lines have been popular for years in Costa Rica, taking tourists zooming through the tropical forest canopy. Now they're cropping up at some North American ski areas, including Whistler and Park City, Utah.

Ready to zip

I joined the McLeans and a handful of other visitors on a Ziptrek tour in February. The zip line course is less than a 10-minute drive from Whistler Village and the whole tour takes just 2 ½ hours. But in the undeveloped, thickly forested valley, we felt far from the glitzy ski resort.

Hours, cost

Ziptrek is open daily year-round. It costs $98 Canadian (about $87 U.S.) for an adult, $78 Canadian (about $69.50 U.S.) for seniors and youths 14 and under. Advance reservations are recommended: 604-935-0001 or www.ziptrek.com There's also a "Tree Trek" walk for those who'd like to see the area but not do the zip lines.

• The maximum weight of a person permitted on a zip line is 275 pounds. For children, the minimum weight is 70 pounds and the minimum age is 6; children who aren't heavy enough can ride the zip lines in tandem with a guide.

• This summer, Ziptrek plans to add two more lengthy zip lines that will whisk visitors all the way back to Whistler Village.

Whistler hosts the Telus World Ski & Snowboard Festival on April 14-23, with professional skiing and snowboarding competition and an outdoor free music festival in Whistler Village, with 50 rock and hip-hop acts. See www.whistler2006.com

Our adventure began in the heart of the village, where throngs of skiers and boarders tromped to the lifts that would whisk them up the mountains. We descended to a cramped locker room in the basement of Carleton Lodge where two Ziptrek guides helped each of us don a helmet and safety harness that encircled the torso, from thighs to shoulders, much like those used by rock climbers.

Looking like trussed teddy bears with the harnesses cinched tightly around our winter jackets, we marched through the village to try out Ziptrek's mini line, a 200-footer by the base of the ski lifts. It gives a taste of the adventure and lets visitors, and the guides, ensure everyone's ready for the big zip lines up in the woods. A guide attached each person's harness to a freewheeling pulley on the zip line and, one by one, we went swooping along, dangling from the cable and thrilled even by the short ride.

Our group of eight definitely was ready for more, with two young boys whooping with excitement. A Ziptrek van shuttled us up past mountainside condos to a "snow cat" — like a big enclosed snowmobile — that clanked through the snowy woods to the Ziptrek course, which begins on the valley's rim.

Boardwalks, twisting wood staircases and mini suspension bridges led through and up the massive spruce, cedar and fir to platforms high in the trees where the zip lines begin. It reminded me of the Ewoks' treehouse village in the "Star Wars" film, the magical place where the teddy-bear-like creatures lived.

Real furry creatures live in these woods, including black bears and lynx. We had lots of time to read about them and other forest creatures on natural-history placards on the platforms; there are long waits, even though it takes only about a minute to zoom along each line, since only one person rides at a time.

At one of the longest zip lines, which swoops diagonally across the narrow valley, the McLeans waited, grinning nervously. When their turns came, they breathed deeply before launching themselves into the air and swooping along the cable to land on a platform high in a tree on the other side.

I followed them, anxiously waiting as the guide attached my safety harness to the zip line's pulley. I stepped forward to the unfenced edge, trying not to look down to the snowbank-edged Fitzsimmons Creek in the valley bottom, about 150 feet below. "When you're ready," said the guide. I screwed my eyes tight shut, stepped into space, and went flying through the air, yelping with fearful glee.

Besides my yelps, the only sound was the high-pitched whir of the pulley's wheels as I surged along the cable, propelled faster and faster by gravity alone. Some people can reach speeds of 50 mph, says Ziptrek marketing manager Laura Gordon; I was probably closer to 35 mph since I'd occasionally fling my arms open in excitement, thus slowing myself with air resistance. The zip lines also are engineered to slow riders as they approach the other end; there's an automatic braking system and the longer cables curve down to the middle then slant uphill. Plus there's another guide at the far end to grab you and slow you down as you land.

Breathtaking

As I swooped along the zip lines, I was half delighted and half terrified, with my heart pounding. It was more thrilling than a big roller-coaster, and the scenery, once I was brave enough to open my eyes, was almost as breathtaking as the ride, from the white-water creek below to the snow-smothered summit of Whistler Mountain glistening thousands of feet above.

I was probably the most nervous and vocal of our group, squealing on each zip-line ride. The rest were braver — and calmer. On the last zip line, where acrobatics are permitted, the pre-teens and teens delighted in twisting and hanging upside down as they careened along the zip line. And Talmadge McLean was relaxed enough to film with his video camera as he came zipping in, giving him a most unusual souvenir of his Whistler visit.